There is no secret. It simply can't be calculated.

Please read our blog posts.

https://blog.lisk.io/lisk-ico-terms-part-i-2e7d01955e4d#.effrbeky4

https://blog.lisk.io/lisk-ico-terms-part-ii-3b50ab74c9b6#.a6jitzft3



If it's really not clear, then I will take a look at the blog posts again. Thank you.